The World at War

The World at War

Participants in World War I

The war in Europe quickly expanded to other parts of the world. European colonies and dominions in the Americas, Africa, Asia and the Pacific provided men and resources to their mother countries. In some cases, these colonial territories themselves became battlegrounds. The entrance of the Ottoman Empire set off fighting in the Middle East and North Africa. Fighting spread to the seas, as both sides tried to prevent shipments of vital supplies to their opponents. When colonies and other possessions are included, most of today’s modern nations participated in some way.

The following nations formally declared war; not all participated in hostilities.

The Allies and Associated Powers

1914

Serbia

Russia

Montenegro

France

Belgium

Great Britain
Includes Canada, Australia, New Zealand, India, South Africa & other British dominions and colonies

Japan

1915

Italy

1916

Portugal

Romania

1917

United States

Cuba

Panama

Greece

Siam

Liberia

China

Brazil

1918

Guatemala

Nicaragua

Costa Rica

Haiti

Honduras

The Central Powers

1914

Austria-Hungary

Germany

Ottoman Empire(Turkey)

1915

Bulgaria

Beyond the Western Front

The Eastern Front

At the outbreak of war, Russia sent its armies into Germany before they are fully mobilized, leading to a horrific early defeat at the Battle of Tannenburg. Russia had better results against Austria-Hungary and the Ottomans in the south, until the Germans stepped in to bolster their allies. But by the end of 1916, staggering casualties and widespread anger on the homefront had brought the army and the nation to the brink of revolution.

Southern Europe

After early Serbian victories, Germany sent men to help Austria-Hungary and convinced Bulgaria to join the Central Powers. Under the combined assault, Serbia was overrun by late 1915. Its place was taken by Italy, which renounced its alliance with Germany and Austria-Hungary. But by late 1916, the Italian front was as deadlocked as the rest of Europe.

The Middle East

The Ottoman Empire (Turkey) joined the Central Powers in late 1914. The British immediately occupied Ottoman oilfields in Mesopotamia, but were unable to advance further. The British attempted an invasion of the Gallipoli peninsula, with disastrous results. A bright spot for the Allies was the revolt of Arab tribes against the Turks, advised by a young British officer named T.E. Lawrence.

Africa

France’s North African colonies sent over 600,000 men to fight in Europe. Egypt served as Britain’s base for the Middle East; the Suez Canal was its lifeline to India. The Ottomans incited uprisings against British and French holdings.

Farther south, the British seized control of Germany’s colonies, but a small German guerrilla force in East Africa tied down hundreds of thousands of Allied troops until the war ended.

On the seas

Most of the action at sea was focused on securing -- or denying -- the passage of vital supplies to the other side. German U-boats (submarines) took a heavy toll on Allied shipping, until international outrage forced Germany to restrict their use. Britain’s naval blockade steadily began to strangle the German war effort and civilian economy. The German and British main fleets fought an inconclusive battle at Jutland, in the North Sea, that had no impact on the outcome of the war.

North America

While the United States remained neutral, Canada, a British dominion, joined the war immediately. Thousands of U.S. citizens cross the border to join the Canadian Army. Canadian units would play an important role in nearly every major battle fought by the British in Europe, proving to be tough, effective troops -- but at a terrible cost. The service and sacrifice of Canadian troops during the war helped forge Canada's distinct identify as a nation, separate from the British Empire.

South America

The countries of South America remained neutral. Allied and German naval ships used South American ports for resupply and repairs. The British and Germans fought a series of small naval battles off the coast of Chile.

South Asia

India, a British colony, sent 1.3 million men to fight in Europe, the Middle East, and Africa. Hoping that wartime service would improve the status of Indians under British rule, Mohandas Gandhi encouraged his countrymen to support the war effort.

The Far East

Japan, an ally of Britain, seized German-controlled territory in China as well as Germany’s colonies in the Pacific. With the European powers focused closer to home, Japan expanded its influence in the region.

Australia/New Zealand

Britain’s most distant dominions responded enthusiastically to its call to arms. The Battle of Gallipoli in 1915 against Ottoman forces, would prove to be a defining moment for both nations. From 1916 onward, Australian and New Zealand (ANZAC) forces served with the British on the Western Front.